Scoring and Separating Glass NOTES: a) Please be patient with the layout. The site template does not allow for proper formatting of text. b) Please read instructions thoroughly before beginning because safety always comes first. c) Tools and oil are available at art glass stores and some residential glass stores. 1. Assemble glass cutter, oil and glass. A glass cutter with a carbide blade is best as it doesn't dull. Use glass cutting oil or kerosene. 2. Clean glass with vinegar or a mixture of 50% ammonia mixed with 50% alcohol plus a good dash of water (I know this equals more than 100%). 3. If doing straight lines, measure and mark the glass. Use a square or ruler as your guide. The guide edge must be high enough that the cutter can run comfortably along it without interference. If using a pattern with curves, carefully trace the pattern piece using a marker. I prefer fine sharpie markers. 4. Dip cutter in oil. 5. The blade of the cutter must score vertical to the glass. To accomplish this hold the cutter upright between index and middle finger with the blade towards the palm, snug it with your thumb. This may seem awkward but the blade will more likely be vertical if you hold it this way rather than as a pencil, although many people do. 6. Place the blade vertically slightly inside the nearest edge of the glass and with a steady, downward pressure roll it along the guide for straight scores, or inside the pattern mark for curved scores, to the opposite edge of the glass. If you find it more comfortable and can be consistent with pressure move the glass cutter towards you rather than away. There is no 'right' direction. Never stop in the middle of the glass. Never rescore over an existing line; you will destroy your cutter. The objective is a smooth, mid tone, comfortable drone sound and a score line with the appearance of a consistent fine line. If you press too hard you will get the gritty sound of the glass shattering. When looked at closely the score line will look shattered. When you try to separate the glass it will not know which direction it is intended to go. If you press too lightly the line will be invisible in places when you wipe the oil off. 7. To separate a straight cut put your bent index fingers beneath the glass, each side of the score line. Leave the further edge resting on the table. Place your thumbs on top each side of the score line and moving your baby fingers closer together and your hands in a circular motion out and down while separating your thumbs, the glass should separate. Do not force it. 8. If it does not separate, carefully turn the glass so the opposite end of the score line is before you and repeat the process. The score line opened the glass on the surface, now you are applying a gentle pressure to further open and separate it through the additional thickness of the glass. As it opens the line will move away from you. Or running pliers are a tool to be used to separate straight lines. The lips are placed perpendicular to the score line with a mark on the top of the top lip lined up along the score line. If you examine them you'll note that the downward slope of the lips encourages the glass to separate in a downward motion as with your hands. Again, allow the majority of the glass to rest on the table. If you must rescore do so a minimum of 2.5 cm. away from the first score line. 9. To separate curves use glass nipping pliers. While the running pliers used to separate straight lines are placed perpendicular to the score line the glass nipping pliers are placed horizontal and right against the score line. Practice tells you where to place these pliers on the score line to get the best separation. Support the glass with one hand while with the other move the nippers gently down, again in a circular motion. Again you are further separating the already scored line. Bravo!! Well done.